Light sensitive apparatus



' Patented July 26, 1938 PATENTSOFFICE LIGHT SENSITIVE APPARATUS Wesley B. Wells, wuunsburgra; assignor to The Union Switch & Signal Company, Swissvale, Pa., a corporation of Pennsylvania Application August so, 1935, Serial No. 38,588

13 Claims. (Cl. 246-130) My invention relates ,to light sensitive apparatus, and is particularly adapted for, though in no way limited to, the control of floodlights at intersections of railways and highways. More 5 specifically, it relates to means for illuminating at night an intersection between arailway and a highway when a train is approaching'or is occupying such intersection so that the train, while occupyingthe intersection, may be distinctly visible to users of the highway.

I will describe two forms of apparatus embodying my invention, and will then point out the novel features thereof in claims.

In the accompanying drawing, Fig. 1- is a diagrammatic view illustrating one form of ap-' paratus embodying my invention, Fig. 2 is a diagrammatic view illustrating a modification of a portion of the apparatus shown in Fig. 1 and also embodying my invention.

Referring first to Fig. 1, the reference character X designates a stretch of railway track over which traflic moves in both directions. The rails i and 2 of track X are divided by insulated joints 3 into sections IT, 2T and ST. Each section is provided with a track battery 4 connected across the rails at one end of the section and with a track relay designated by the reference character R with a distinguishing prefix connected across the rails at the other ,end of the section.

The track relays ITR and 3TB constitute the tworelay elements of an interlocking relay designated by the reference character M.

The section 2T includes an intersection of the railway and a highway designated by the reference character H.

A light sensitive device designated in general by the reference character Q is located adjacent the intersection. The device Q, as here shown,

comprises a photoelectric generator G exposed 40 to the atmosphere and a relay P connected to the generator G. The generator G has the property of converting the energy of light rays into electrical energy. A number of such photoelectric generators are well-known, one such generator being described in Letters Patent of the United States No. 1,970,135, issued August 14, 1934, to Lars O. Grondahl and Paul H. Geiger. When the amount of daylight adjacent the intersection is above a predetermined value, the gener- 59 ator G will generate suflicient current to pick up the relay P whereas, when the amount of day-' light decreases below this predetermined value, the generator G will not supply suflicient current to maintain relay P in its picked up condition.

55 Located adjacent the intersection is a lamp designated by the reference character F and which may be a floodlight. The floodlight F is so located that, when. lighted, the intersection will be illuminated so that any train or trains occupying the intersection will be distinctly visible 5 to users of the highway H.

Associated with the floodlight F is a normally deenergized stick relay S. The relay S is. effective, when energized, to light the floodlight by virtue of a circuit which passes from terminal B 10 of a suitable source of energy through front contact ill of relay S and lamp F to terminal 0 of the same source of energy.

The relay S will be energized upon the deenergization of any of the track relays provided that 15 relay P is in its deenerglzed condition. That is, when the amount of daylight adjacent the intersection decreases to such value that back contact .lease upon the approach of nightfall and will remain in such condition until the appearance of 30 daylight again. The back contact 5 of relay P, therefore, under ordinary conditions is not required to make and break thecircuit for the operating current for relay Sbut is only required to carry the operating current of the lat- 35 ter relay. The contact 5, therefore, may have an extremely long life even though it may be of delicate construction such as is usually found in light sensitive devices.

It will be noted that the magnets ITR. and 3TH. 40

of interlocking relay M are controlled over front contacts I I and I2 of track relay ZTR. That is, both magnets ITR and 3TB will be deenerglzed when the section 2T is occupied by a train. This insures that the interlocking feature of re- 45 lay M will operate properly in the event a short car or engine passes over the intersection. That is, if a car or engine of a length such as to permit it to lie wholly within section 2T passes over the intersection, the interlocking feature of relay M will not be disabled since the initially deenerglzed magnet of the interlocking relay cannot pick up before the other magnet becomes deenerglzed.

It will be readily apparent that if a train section 2T, the relay S will be maintained in its energized condition even though the rear of the train may vacate section IT. That is, the floodlight F. will be lighted as long as any portion of the train occupies section 2T. When the rear of the train leaves section 2T, the interlocking feature of relay M will prevent the closing of back contact 8 of magnet STR so that the relay S will become deenergized. When the relay S is deenergized, the floodlight F, of course, will be extinguished.

Referring now to Fig. 2, the stick relay Sis here shown as a normally energized relay which, when deenergized, so that its back contact i3 becomes closed, is effective for lighting the floodlight F.

The relay S is provided with three easily traced pick-up circuits which include contacts ll, I5

and I6, respectively, of relays ITR, 2TB. and HR, respectively, and is provided with an easily traced stick circuit which includes front contact ll of relay P and front contact 8 of relay S.

It will be noted that front contact I! of relay -P is included in the stick circuit only for relay S and, therefore, as previously explained for the apparatus shown in Fig. 1, is not ordinarily required to make and break the circuit for the operating current for relay S but is only required to carry such current after the latter relay'isin its picked up condition.

When relay P is in its deenergized condition so that the stick circuit for relay S is opened, it will be readily apparent that the relay S will become deenergized if any of the track relays ITR, 2TB. or 3TB. is released. In other words, the floodlight F will be lighted in a manner similar to that described for the apparatus shown in Fig. 1.

Contacts II and I6 of magnets I'IR and 3TB of interlocking relay are flagman'contacts so that such contacts do not open for trains receding from the intersection. The relay S, therefore, will become energized so that floodlight F will be extinguished whenever a train receding from the intersection leaves section IT.

From the foregoing, it will be seen that I have provided a simple and reliable means for illuminating at night an intersection of a railway and a highway so that a train: occupying such intersection is distinctly visible to users of the highway. Furthermore, the apparatus embodying my invention utilizes a relay controlled by a photoelectric generator which relay may be of delicate construction so as to operate on the extremely small current usually supplied by such generators, since the contacts of this relay are ordinarily not required to make and break energized circuits.

Although I have herein shown and described only two forms of apparatus embodying my invention, it is understood that various changes and modifications may be made therein within the scope of the appended claims without departing from the spirit and scope of my invention.

Having thus described my invention, what I claim is:

1. In combination with a section of railway track having a track relay associated therewith, an electric lamp, a normally deenergized stick relay, means efiective as long as said stick relay is energized to light said lamp, a photoelectric generator located adjacent said lamp, another relay controlled by said photoelectric generator and deenergized when the amount of daylight is reduced to a predetermined value, a pick-up circuit for said stick relay including a back contact of said track relay and aback contact of said other relay, and a stick circuitfor said stick relay including its own front contact and said back contact of said track relay.

2. In combination with a section of railway track having a track relay associated therewith, an electric lamp, a normally energized stick relay effective when deenergized to light said lamp, a photoelectric generator located adjacent said lamp, another relay controlled by said photoelectric generator and deenergized when the amount of daylight is reduced to a predetermined value, a stick circuit for said stick relay including its own front contact and a front contact of said other relay, and a pick-up circuit for said stick relay including a front contact of the said track relay.

3. In combination, a stretch of railway track divided into two end sections and an intermediate section, an interlocking relay controlled by trailic conditions in the three sections, a fioodlight, a highway intersection in said intermediate section illuminated by said fioodlight, a light sensitive device responsive to the amount of daylight adjacent said intersection, and means controlled by said interlockingj relay and by said light sensitive device for governing said floodlight.

4. In combination, a stretch of railway track divided into two end sections and an intermediate section each having; a track relay, the track relays for the end sections being the magnets of an interlocking relay and both controlled by the track relay for the intermediate section, a highway intersection in said intermediate section, a. floodlight for illuminating said intersection, a photoelectric generator located adjacent said intersection, another relay controlled by said photoelectric generator, and means governed by said interlocking relay and by said track relay for the intermediate section as well as by said other relay for controlling said floodli'ght.

5. In combination, a device having an initial condition but operable to a different condition, a lamp, light sensitive apparatus responsive to the amount of daylight adjacent said device, means controlled by said light sensitive apparatus and by said device for lighting said lamp when said device is operated to its different condition provided the amount of daylight is then below a predetermined value, and means efiective thereafter to light said lamp as long as said device remains in its diiierent condition regardless of subsequent changes in the amount of daylight.

6. In combination, a device having an initial condition but operable to a different condition, light sensitive apparatus responsive to the amount of daylight adjacent said device. a relay normally in one condition, means controlled by said device and by said light sensitive apparatus for causing said relay to assume another condition when said device is operated to its diflerent condition provided the amount of daylight is then below a predetermined value', means eiIective thereafter to maintain said relay in such other condition as long as said device remains in its different condition regardless of subsequent changes in the amount of daylight, a lamp, and means for lighting-said lamp as long as said relay is in said other condition.

'2'. In combination, a device having an initial condition but operable to a difierent condition, a photo-electric generator exposed to daylight adjacent said device, a relay controlled by said photoelectric generator and arranged to assume one condition or another condition according as the amount of daylight is above or below respectively a given value, a lamp,'means controlled by said device and by said relay for lighting said lamp when said device is operated to its different condition provided said relay is then in its other condition, and means efiective thereafter to light said lamp as long as said device remains in its diiierent condition regardless of whether said relay is in said one condition or said other condition.

8. In combination, a section of track including a track relay, a lamp, a light sensitive device responsive to the amount of daylight adjacent said section, means controlled by said light sensi-. tive device and by said track relay for fighting said lamp when said relay is released provided the amount of daylight is then below a given value, and means effective thereafter to light said lamp as, long as said track relay remains released regardless of subsequent changes in the amount of daylight.

9. In combination, a section of railway track including an intersection with a highway, a flood lamp for illuminating a portion of such intersection, a relay controlling the supply of current to said floodlamp, a circuit controlled by said relay through which current may be supplied to its winding, photoelectric means responsive to the amount of daylight at such intersection and also controlling said circuit, and a track relay associated with said track section and controlling a circuit through which current may be supplied to the winding of said relay.

10. In combination, a section of railway track including an intersection with a highway, a floodlamp for illuminating a portion of such intersection, a control relay controlling the supply of ourrent to said fioodlamp, a first circuit for supplying current to the winding of said relay, a second circuit for also supplying current to the winding of said relay, photoelectric means responsive to the amount of daylight at such intersection and controlling one of said circuits, and a track relay associated with said track section and controlling the other of said circuits, one of said circuits being also controlled by said control relay.

11. In combination, a section of railway track including an intersection with a highway, 2. fioodlamp for illuminating a portion of such intersection, a control relay controlling the supply of current to said floodlamp, a first circuit for supplying current to the winding of said relay, a second circuit for also supplying current to the winding of said relay, photoelectric means responsive to the amount of daylight at such intersection and controlling one of said circuits, the other of said circuits being controlled by said relay, and a track relay associated with said track section and con trolling both of said circuits.

12. In combination, a section of railway track including an intersection with a highway, a floodlamp for illuminating a portion of such intersection, a relay having a-winding and having a movable contact operated only when said winding is deenergized to establish a circuit to supply cur. rent to said floodlamp, a first circuit through which current may be supplied to said relay winding, means operative when and only when said relay winding is energized to establish said first circuit, photoelectric means responsive to the amount of daylight at such intersection for also controlling said first circuit, a second circuit through which current may be supplied to said relay winding, and a track relay associated with said track section and controlling said second circuit.

13. In combination, a section of railway track including an intersection with a highway, a floodlamp for illuminating a portion of such intersection, a relay having a winding and having a movable contact operated when and only when said winding is energized to establish a circuit to supply current to said floodlamp, a first circuit through which -current may be supplied to said relay winding, means operative when and only when said relay winding is energized to establish said first circuit, a second circuit for supplying current to said relay winding, photoelectric means responsive to the amount of daylight at such intersection and controlling said second circuit, and a track relay associated with said track section and controlling the supply of current to said first and second circuits.

WESLEY B. WELLS. 

